Libraw just delivers decoded raw data to prosessing application. Processing (e.g. demosaicing, white balancing, channel mixing, etc, while demosaicing is not needed for Foveon data) is performed in calling application (e.g. Affinity).

LibRaw contains some postprocessing code (derived from dcraw), it is not intended to use in any professional-level application, this is mostly 'proof of concept'. We do not have any plans to change LibRaw postprocessing code.

Your demarcation is essentially correct.